OBJECTIVETo separate and identify chemical constituents from stem barks of male plants of Populus tomentosa.

METHODFresh stem barks of P. tomentosa were extracted with methanol to obtain extracts which were suspended in water and blended successively with petroleum ether, ethyl acetate and n-butanol. Various chromatographic techniques were used to separate and purify the constituents extracted with ethyl acetate and n-butanol fractions. Their structures were identified on the basis of their physicochemical properties and spectral data.

RESULTTwelve compounds were separated with ethyl acetate and n-butanol fractions and identified as benzoic acid (1), daucosterol (2), tremuloidin (3), rhamnocitrin (4), sakuranetin (5), 7-O-methylaromadendrin (6), isograndidentatin A (7), siebolside B (8), sakuranin (9), micranthoside (10), alpha-D-glucopyranose (11), and sucrose (12).

CONCLUSIONCompounds 4-12 were separated from this plant for the first time. Of them, compound 10 was separated from this plant genus for the first time.

The genus Populus (poplar) belonging to the Salicaceae family has been used in traditional medicine, and its several species show various pharmacological properties including antioxidant and anti-inflammatory effects. No study regarding protective effects of Populus species against cerebral ischemia has been reported. Therefore, in the present study, we examined neuroprotective effects of ethanol extract from Populus tomentiglandulosa (Korea poplar) in the hippocampal cornu ammonis (CA1) area of gerbils subjected to 5 minutes of transient global cerebral ischemia. Pretreatment with 200 mg/kg of P. tomentiglandulosa extract effectively protected CA1 pyramidal neurons from transient global cerebral ischemia. In addition, glial fibrillary acidic protein immunoreactive astrocytes and ionized calcium binding adapter molecule 1 immunoreactive microglia were significantly diminished in the ischemic CA1 area by pretreatment with 200 mg/kg of P. tomentiglandulosa extract. Briefly, our results indicate that pretreatment with P. tomentiglandulosa extract protects neurons from transient cerebral ischemic injury and diminish cerebral ischemia-induced reactive gliosis in ischemic CA1 area. Based on these results, we suggest that P. tomentiglandulosa can be used as a potential candidate for prevention of ischemic injury.
Astrocytes ; Brain Ischemia* ; Calcium ; Ethanol ; Gerbillinae* ; Glial Fibrillary Acidic Protein ; Gliosis* ; Hippocampus ; Humans ; Medicine, Traditional ; Microglia ; Neurons* ; Neuroprotective Agents ; Populus* ; Pyramidal Cells ; Salicaceae

The soil bacterium Agrobacterium tumefaciens is a plant pathogen that causes crown gall tumors by infecting the wounded dicotyledonous plants and subsequent integration of bacterial DNA into plant nuclear DNA. Virulent A. tumefaciens strains harbor a large Ti (tumor–inducing) plasmid that carries genes essential for tumorigenesis. In the present study, 13 strains (Malus pumila Mill; A₁₋₃, Populus monilifera; W₁₋₆, Populus tomentiglandlosa; P₁₋₃ and Rosa species; R₁) of Agrobacterium isolated in korean crown gall tumors and plasmids were observed in 6 strains (W₂, W₃, W₆, P₁, P₃ and A₂). The test for crown gall tumor formation was resulted only in ATCC15955 and KW2 strains inoculated into the stem of sun flower and the development was observed for 4 and 6 weeks after inoculation. Above two Ti plasmids (pTi) were purified by cesium chloride-ethidium bromide density gradient centrifugation and digested with restriction enzyme and fragments of pTiATCC15955 and pTiKW₂ observed by EcoR I ; 25&27, Hind III ; 23&21, BamH I ; each 20 and Hpa I ; 12&27. And sizes of pTiATCC15955 and and pTiKW₂ calculated as 200 and 87 kbases. Octopine was isolated from tumor tissue (W₁₋₆ and P₁₋₃) and these strains confirmed as octopine type.
Agrobacterium tumefaciens ; Agrobacterium* ; Carcinogenesis ; Centrifugation, Density Gradient ; Cesium ; DNA ; DNA, Bacterial ; Flowers ; Korea* ; Plant Tumor-Inducing Plasmids ; Plant Tumors ; Plants ; Plasmids* ; Populus ; Rosa ; Soil ; Solar System ; Wounds and Injuries

Poplar(Pupulus x Xiao zhannica, cv. "balizhuang-yang") transferred with mtl-D gene was used as an experimental material. Through tissue culture, aquaculture and pot culture transgenic poplars are tested with variant Nacl salt gradient. In it transgenic poplar raises its initial days for differentiation, differentiation rate, bud intensity, bud height and growth potential than control plant. At the same time, the transgenic poplar has higher rooting rate and more top roots, side roots and higher root length than control under the same salt stress. The result shows that the transgenic poplar has better tolerance ability than control plant in the salt 4@1000 contensity mediums.
Adaptation, Physiological ; genetics ; Dose-Response Relationship, Drug ; Drug Resistance ; genetics ; Plants, Genetically Modified ; Populus ; drug effects ; genetics ; growth & development ; Sodium Chloride ; pharmacology

Animals ; Asthma/pathology* ; CD4-Positive T-Lymphocytes/immunology* ; China/epidemiology* ; Disease Models, Animal ; Immunoglobulin E/blood* ; Incidence ; Lung/pathology* ; Mice ; Pollen/chemistry* ; Populus/adverse effects* ; Prevalence

Arabidopsis ; metabolism ; Catalytic Domain ; Dimerization ; Glutathione ; metabolism ; Magnetic Resonance Spectroscopy ; Populus ; metabolism ; Protein Disulfide Reductase (Glutathione) ; chemistry ; metabolism ; Protein Isoforms ; chemistry ; metabolism ; Protein Structure, Tertiary

In a large number of a1lergic cases, inhalant allergens, particularly airborne pollens and mo1ds am important causative, triggering agents in respiratory, even in skinanergy. It is essential for diagnosis and treatment of airborne allergy to survey the airborne pollen and mo1d in the patient's living area. Rotorod samp1er was installed on the well-ventilated rooftop of Hanyang Kuri Hospital in Kuri-shi, Kyunggi-do as the vicinity of Seoul. Airborne allergens were collected from October 1, 1995 to September 30, 1996 daily and were stained with Calberla`s fuchsin and were identified, counted under the light microscope (400Xfor pollen, 1000Xfor mold). The data were compared with the local daily weather report. The airborne pollen was found from 12th February to 22nd December. The maximal period for pollen collection was 7th-25th May (Maximal count:492 grains/ August. There were Alnus, Betula, Pinus, Quercus, Acer, Ulmus, PopuluS, Cupressaceae, Ginkgo, Corylus, Salk in the tree season from middle of February to middle of July. The grass season ranged from middle of March to end of November. There were Artemisia, Ambrosia, HumuluS, Chenopodium-Amaranthus, rumex, Plantago, Trifoium, Humulus, Chrysanthemum, Cyperus in the weed season ranged from middle of July to end of December. Airborne molds were collected all through the year except JanuaIgamma but, counted maximally from the middle of June to end l August. There were CladosPorium, Alternaria, ascospore of Leptospheria, Periconia, Myxomycete, Drechs1era, Rust urediniospores, Basidiospore, ToruIa, Xylariaceae, IOidimn, Nigrospom, Stempi1y1ium, Amphispheda, Fusarium, Aspergil1us. In Korea, there are great number of the allergic patients, but we have had a little records and data about study of relationship between the allergic diseases and airborne environmental allergens. we will reported those results completely in future.
Acer ; Allergens ; Alnus ; Alternaria ; Ambrosia ; Artemisia ; Betula ; Chrysanthemum ; Cladosporium ; Corylus ; Cupressaceae ; Cyperus ; Diagnosis ; Fungi* ; Fusarium ; Ginkgo biloba ; Gyeonggi-do* ; Humans ; Humulus ; Hypersensitivity ; Korea ; Myxomycetes ; Pinus ; Plantago ; Poaceae ; Pollen ; Populus ; Quercus ; Rosaniline Dyes ; Rumex ; Seasons ; Seoul ; Trees ; Ulmus ; Weather

Dehydration-Responsive Element Binding ( DREB) transcription factors, specifically binding with dehydration reponsive element (DRE), activate a variety of stress-responsive genes in plants under abiotic stresses (dehydration, high salt and low temperature). Using PCR and homologous EST search, we isolated a DREB-like gene from Yinxin poplar (Populus alba x P. alba var. pyramidalis) named PaDREB2. Yeast One-hybrid experiment demonstrated that PaDREB2 protein could function as a DREB transcription factor activating target gene expression by specifically binding to DRE cis-element. To study the expression pattern of PaDREB2, RT-PCR was carried out. And the results showed that PaDREB2 is induced by low temperature, drought and high salt.
Amino Acid Sequence ; Cloning, Molecular ; Cold Temperature ; Droughts ; Expressed Sequence Tags ; Gene Expression Regulation, Plant ; Molecular Sequence Data ; Phylogeny ; Plant Proteins ; genetics ; metabolism ; Populus ; genetics ; metabolism ; Stress, Physiological ; Transcription Factors ; genetics ; metabolism

The United Nations Environment Program estimates that approximately 20% of agricultural land and 50% of cropland in the world is salt-stressed. The gene NHX (Na+/H+ exchanger) encodes functional protein that catalyzes the countertransport of Na+ and H+ across membranes and may play an important role in plant salt tolerance. To clone the NHX from the wild plant Populus euphratica collected in Tarim basin and Xinjiang Wujiaqu district into a T-vector, designed primer was used to amplify 1kb NHX cDNA fragment with RT-PCR. Total RNA was extracted from Populus euphratica tissue (plant tissue was collected from Tarim basin and Xinjiang Wujiaqu district and stored in liquid nitrogen) according to the Plant RNA Mini Kits of Omega. First cDNAs were synthesized from 1 microg total RNA of Populus euphratica seedling. A pair of primers were used to perform RT-PCR. The amplified DNA fragment was purified and cloned into pMD18-T vector. However, 1kb and 2.3kb fragment were obtained from Tarim basin and Xinjiang Wujiaqu district and named as PtNHX and PwNHX, respectively. Sequence analysis reveals that the cloned PtNHX fragment of Populus euphratica contains partial NHX coding region with 98%, 86%, 84% and 80% identity comparing with Atriplex gemelini, Suaeda maritima, Arabidopsis thaliana and Oryza sativa, respectively. This analysis suggests that NHX gene would be highly conserved in terms of evolution in plant; and it also suggests that the NHX gene of Populus euphratica also would have the similarity with that of Arabidopsis. It may be of great importance in improvement of the plant salt tolerance and breed of crop. At the same time, sequence analysis shows that PwNHX gene includes a coding region about 1350bp with 99% identity comparing with transposon Tn10 IS10-left transposase of Shigella flexneri. On the one hand, the NHX gene may lose its function because it was inserted a fragment in coding region. On the other hand, its product may play a important role in salt tolerance. Populus grow in saline soil. It speculates that it may have other salt tolerance mechanism in Populus. The transposon can be used as transposon tagging to clone other genes and it will help us to understand farther the salt tolerance mechanism.
Amino Acid Sequence ; DNA Transposable Elements ; genetics ; DNA, Complementary ; Genetic Vectors ; genetics ; Molecular Sequence Data ; Plant Proteins ; chemistry ; genetics ; Populus ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Alignment ; Sequence Homology, Amino Acid ; Shigella flexneri ; genetics

Plant betaine aldehyde dehydrogenase (BADH) is a physiologically important enzyme in response to salt or drought stress. In this study, two BADH genes (PeBADH1 and PeBADH2) were cloned from Populus euphratica. Both PeBADH1 and PeBADH2 genes encode the proteins of 503 amino acid residues, with a calculated molecular mass of 54.93 kDa and 54.90 kDa, respectively. Reverse transcription PCR showed the divergence of expression pattern between the PeBADH1 and PeBADH2 genes in P. euphratica. The recombinant PeBADH1 and PeBADH2 proteins were overexpressed in E. coli, and purified by Ni-affinity chromatography. The PeBADH2 protein had 1.5-fold higher enzymatic activity towards the substrate aldehyde than PeBADH1 protein. The PeBADH1 protein revealed higher thermal stability than PeBADH2 protein. These results indicated obvious functional divergence between the PeBADH1 and PeBADH2 genes.
Amino Acid Sequence ; Betaine-Aldehyde Dehydrogenase ; biosynthesis ; genetics ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Gene Expression Regulation, Plant ; physiology ; Molecular Sequence Data ; Plant Proteins ; biosynthesis ; chemistry ; genetics ; Populus ; genetics ; Protein Isoforms ; chemistry ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Substrate Specificity